Vinge is a real world, honest to goodness Computer Science professor. His books are accurately described as hard science fiction. This story describes a later chapter in Pham Nuwen's life. Pham was part of the space faring group of merchants, the Qeng Ho, benefiting from the time dilation effect of interstellar travel. They did not know they were trapped in the Slowness, a part of the universe where true faster than light travel was impossible. This story looks a a bigger slice of the universe where people can ascend or transcend to a higher plane where technology becomes synonymous with magic. Keeping in mind Arthur C. Clark's admonishment that any sufficiently advanced technology is indistinguishable from magic
Ravena Bergsndot is a librarian at Relay, a network node akin to DropBox on steroids. A repository and clearing house of data. Information is king and as a clearing house Relay is paramount in it's neighborhood. A perversion arises that threatens the known universe. Ravena is partnered with Pham and they become shipmates of two plant people, Geenstalk and Blueshell.
The shipmates dive into the deeps of the Slowness watching their technology degrade to find a weapon to battle the perversion and to incidentally rescue some children marooned there through no fault of their own. Mixed into this mélange of aliens, the shipmates meet pack mind folks who have woes of their own.
Vinge has captured multitasking in his story telling. The stories culminate together and are tied up neatly.
I highly recommend it.
Fan Based web site: http://mindstalk.net/vinge/ /This book may have been received free of charge from a publisher or a publicist. That will NEVER have a bearing on my recommendations.